Download Presentation - CEUR

Using WordNet glosses to
refine Google queries
Jan Nemrava
Department of Information and Knowledge Engineering,
University of Economics, Prague
[email protected]
The Present
• Web search results affected by synonymy
• Inexperienced users inserting too general
queries
• Ambiguity of inserted queries
• Goal: Discover synonymy in proper nouns
• Pankow inspiration
Some of solutions
• Offer query refinement
– Zoom in
– Zoom out
• Ask Jeeves (ask.com)
• Term suggestions
– Not grammatically and meaningfully perfect
• Google Suggest Beta, Centrum, Seznam
(http://www.google.com/webhp?complete=1&hl=en)
• Offer arranged results
– According to synonymy class
– Vivisimo
Discovering synonymy
• Information Sources
– WordNet
– monothetic clustering
– Google API
– NLP tools
– Hearst Patterns
WordNet and NLP
• WordNet contains 150,000 words
organized in over 115,000 synsets
• Each word has a short description gloss
• Key idea is to check if nouns in glosses
contain the meaning (i.e. superclass) of
the word.
• NLP
– Stop words list and POS tagger
Hearst Patterns
• lexico-syntactic patterns indicating the
existence of class/subclass relation in
unstructured data sources
•
•
•
•
•
NP0 such as NP1, NP2,. . .,NPn−1 (and | or) NPn
such NP0 as NP1, NP2,. . .,NPn−1 (and | or) NPn
NP1, NP2,. . ., NPn−1 (and | or) other NP0
NP0 (including—especially) NP1, NP2,. . ., NPn−1 (and | or) NPn
and very common ”NPi is a NP0”
Technique
• get all synonyms and their glosses for given word from
WordNet
• Process all glosses with NLP tools to get candidate
nouns
• Apply “is a” pattern on each of candidate nouns and
count the number of results
• Validate the results with “and other” pattern
• Compare the results and give the most probable
hypernym
Extracting “candidate nouns”
• Considering the proper noun PLUTO
- 3 meanings in WordNet (planet, God, cartoon)
Glosses
– a small planet and the farthest known planet from the sun; has
the most elliptical orbit of all the planets
– (Greek mythology) the god of the underworld in ancient
mythology; brother of Zeus and husband of Persephone
– a cartoon character created by Walt Disney
Extracting “candidate nouns”
• Considering the proper noun PLUTO
- 3 meanings in WordNet (planet, God, cartoon)
Glosses
– a small planet and the farthest known planet from the sun; has the
most elliptical orbit of all the planets
– (Greek mythology) the god of the underworld in ancient mythology;
brother of Zeus and husband of Persephone
– a cartoon character created by Walt Disney
– Candidate nouns
– planet;sun;orbit;planets;
– Greek;god;underworld;mythology;brother;Zeus;husband;Persephone;
– cartoon;character;Walt;Disney;
Extracting “candidate nouns”
• Considering the proper noun PLUTO
- 3 meanings in WordNet (planet, God, cartoon)
Glosses
– a small planet and the farthest known planet from the sun; has the
most elliptical orbit of all the planets
– (Greek mythology) the god of the underworld in ancient mythology;
brother of Zeus and husband of Persephone
– a cartoon character created by Walt Disney
– Candidate nouns
– planet;sun;orbit;planets;
– Greek;god;underworld;mythology;brother;Zeus;husband;Persephone;
– cartoon;character;Walt;Disney;
Applying Two Patterns
• ”Pluto is a planet” (1550), ”Pluto is planet” (145)
• ”Pluto is a sun” (2), ”Pluto is sun” (0)
• ”Pluto is a orbit” (0), ”Pluto is orbit” (1)
• ”Pluto is a planets” (0), ”Pluto is planets” (0)
For each of 16 candidate nouns create similar pattern and search for it
Validation
• ”Pluto and other planets” (57)
• ”Pluto and other planet” (0)
• ”Pluto and other suns” (0)
• ”Pluto and other sun” (0)
•
•
Problem with adjectives
Plural problem
Candidate nouns
planet;sun;orbit;planets;
Applying Two Patterns
• ”Pluto is a planet” (1550), ”Pluto is planet” (145)
• ”Pluto is a sun” (2), ”Pluto is sun” (0)
• ”Pluto is a orbit” (0), ”Pluto is orbit” (1)
• ”Pluto is a planets” (0), ”Pluto is planets” (0)
For each of 16 candidate nouns create similar pattern and search for it
Validation
• ”Pluto and other planets” (57)
• ”Pluto and other planet” (0)
• ”Pluto and other suns” (0)
• ”Pluto and other sun” (0)
•
•
Problem with adjectives
Plural problem
Results
• Test set: 50 nouns from travel, space and
zodiac
Results
• Bad results
Drawbacks and Future
• Drawbacks
– No proximity search in Google
– Slow response of Google API
– Lot of queries to discover one meaning
• Future:
– Add another validation step
– Discover collocations in results
– Discover Named Entities
Questions?
Thank you for your attention